The present invention relates to a retractable screen, such as a venetian blind, a folding blind or curtain or a roller blind which can be gathered together.
One known form of such screen comprises a headrail, lateral profiles extending generally perpendicular from each end of the headrail, a bottom rail having end portions movable in said lateral profiles and draw-cords connected to the bottom rail. The draw-cords may be connected to a slide which is mounted for movement along the lateral profile so that movement of this slide actuates the bottom rail via the draw-cords. The slide, however, does not permit the bottom rail to move up and down other than by means of the slide, so that, particularly in the event of failure or seizure of the slide, the blind cannot be moved up or down.